WASHINGTON -- Former Wisconsin Sen. Russ Feingold, whose lone vote against the Patriot Act made him a hero among civil libertarians, said he has no problem with the killing of U.S.-born cleric Anwar al-Awlaki in a drone attack in Yemen last fall.

"I'm very pleased that he was taken out," said Feingold, who spoke to The Huffington Post ahead of the Tuesday release of his new book, "While America Sleeps." "I do believe he was part and parcel of al Qaeda. I do think it is legitimate to go after al Qaeda operatives."

The clandestine assassination of an American citizen without a trial sparked a legal and moral debate last year that echoed a similar one after 9/11 as lawmakers drafted the now controversial Patriot Act. A secret Obama administration memo leaked soon after the strike concluded that Awlaki could be legally targeted if it was not possible to capture him alive.

Even as he told The Huffington Post in an interview that "Americans have metaphorically gone back to sleep when it comes to constitutional intrusions in the name of fighting terrorism," the former member of the Senate Intelligence Committee made clear that in Awlaki's case, exceptions should be made.